Dental floss



April 26, 1966 M. s. KANBAR 3,247,857.

DENTAL FLOSS Filed June 23, 1965 1 N VEN TOR.

United States Patent 3,247,857 DENTAL FLOSS Maurice S. Kanbar, 2 E. 75thSt, New York, N.Y. Filed June 23, 1965, Ser. No. 466,229 7 Claims. (Cl.132-93) This application is a continuation-in-part of application SerialNo. 276,564, filed April 29, 1963 now abandoned. This invention relatesto a dental floss made of exceptionally soft material, the floss havinga smooth surface and a high tensile strength whereby the teeth and gumsmay be cleaned efliciently and without injury thereto.

Dental floss is used to dislodge food particles and other foreignmaterial wedged between the teeth. The use of floss supplements thetoothbrush, for brushes cannot penetrate the constricted region betweenadjacent teeth. Since dental floss is forced between the teeth and makescontact with the gums, to avoid damage it is important that the flosssurface be free of abrasion. At the same time, the floss must be strong,for it is subject to tension when forced between the teeth by the user.

Among the materials generally used for dental floss are multi-strandsilk and cotton or nylon yarns which are rendered smooth by applying acoating of a waxlike substance, such as parafiin or solid polyethyleneglycols. While the use of strands adds to the strength of the floss, therupture or unravelling of any strand when the floss is used, results ina surface discontinuity which is injurious to the user.

Accordingly, it is the main object of this invention to provide a dentalfloss which is of exceptionally soft material, having a smooth surfaceentirely free of abrasion, the floss nevertheless being of high tensilestrength.

More specifically, it is an object of the invention to pro vide a dentalfloss of superior quality formed by loosely twisting a tape of anoriented polymer, such as a polyethylene or polyamid into a helixforming a small compressible tube.

For a better understanding of the invention, as well as other objectsand further features thereof, reference is made to the followingdetailed description to be read in conjunction with the accompanyingdrawing, wherein:

FIG. 1 is a perspective view of the tape used in making the floss;

FIG. 2 shows the tape after stretching;

FIG. 3 shows the tape after twisting to form floss; and

FIG. 4 shows the compression of the floss as it passes between adjacentteeth.

Referring now to the drawing, and more particularly to FIG. 1, thestarting material for the dental floss is a smooth film ltl of uniformthickness formed from an extruded polymer, such as Saran, polyethylene,polyesters, or polyamides. Such films in broad widths are produced bythe melt extrusion process, and for present purposes a fine film ofapproximately 0.00015" thick is used, which is slit into a tape ofapproximately one inch in width. Alternatively, the film may be extrudedfrom a die directly in the desired tape Width.

The tape is then passed through snub orienting or drawing rollsconstituted by feed rolls and draw rolls operating at different speeds,the speed ratio therebetween determining the extent to which the tape isstretched. Stretching of the tape serves to orient the molecularstructure of the film and thereby increase its tensile strength. Theyarn may be cold or hot drawn. In hot-drawing, heat is supplied to thedrawing point, the drawing load of the tape being thereby lowered morethan the breaking load, enabling a greater draw ratio to be achieved.

In accordance with the present invention, the tape is stretched toapproximately 3 times its initial length to produce a ribbon 11, asshown in FIG. 2, whose width is about one-half that of the initial tape10 and about half as thick. The ribbon is much stronger than theunstretched tape and is very soft.

The ribbon 11 is then twisted approximately 1 to 3 turns per inch toproduce a floss 12 having the desired characteristics. Because of theloose twist, the ribbon forms a helix which produces a continuous hollowtube of very small diameter. As shown in FIG. 4, when the tubular andvery soft floss 12 passes in the very narrow passage between teeth T andT the floss yields and the tube is compressed. Thus the floss is bothsoft and compressible and when passed through a constricted dentalregion tends to yield to avoid injury to dental surfaces. On the otherhand, the exceptional strength of the floss and its naturally smoothqualities render it highly suitable for its intended purpose.

Because the tape is loosely twisted, this creates crevices in the flosswhich tend to catch and dislodge debris from between the teeth when thefloss is passed therethrough.

While there has been shown and described a preferred embodiment ofimproved dental floss in accordance with the invention, it will beappreciated that many changes and modifications may be made thereinwithout, however, departing from the essential spirit of the inventionas defined in the annexed claims.

What is claimed is:

1. A dental floss constituted by an extruded polymer ribbon which isstretch-oriented to increase its strength and which is loosely twistedinto a helix forming a hollow and compressible tube.

2. A floss as set forth in claim 1, wherein said ribbon is approximatelyone-half inch wide and of a thickness in the order of .000075".

3. A floss as set forth in claim 1, wherein said film is formed of apolyamide.

4. A floss as set forth in claim 1, wherein said film is formed of apolyethylene.

5. A floss as set forth in claim 1, wherein said film is formed of apolyester.

6. The method of making dental floss, comprising the steps of extrudinga polymer film of uniform thickness, slitting said film into a tapehaving a width of about one inch, stretching said tape to orient itsmolecular structure to form a ribbon, and twisting said ribbon into ahelix to form a hollow and compressible tube.

7. The method of making an abrasion-free and strong dental floss,comprising the steps of:

(a) extruding a polymer into a tape having a width of about one inch anda uniform thickness not exceeding .00015 of an inch,

(b) stretching said tape to orient its molecular structure and to form arelatively narrow ribbon whose width and thickness are substantiallysmaller than that of the tape, and

(c) twisting said ribbon loosely about one to three turns per inch intoa helix to form a hollow tube constituting a compressible floss havingexceptional strength and smoothness.

References Cited by the Examiner UNITED STATES PATENTS 1,149,376 8/1915Leonard et a1 132-93 1,832,604 11/1931 Wupper l32-93 2,337,834 12/1943Peters 13293 2,772,205 11/1956 King l32--93 RICHARD A. GAUDET, PrimaryExaminer.

1. A DENTAL FLOSS CONSTITUTED BY AN EXTRUDED POLYMER RIBBON WHICH ISSTRETCH-ORIENTED TO INCREASE ITS STRENGTH AND WHICH IS LOOSELY TWISTEDINTO A HELIX FORMING A HOLLOW AND COMPRESSIBLE TUBE.